Final (I think) fixes to the theme downloader

- Added a cancel button and associated logic when downloading themes

- Made the text colour be the opposite of the progress bar below it

- Added a try catch around extracting a theme, just in case

- Moved the dialog handling to a task, which I was hoping would allow the progress bar to update but sadly still no

- The download dialog is only created once and then reused, so it doesn't pop up twice when downloading the heroes mod loader theme

Author: ZackWilde27

source/Reloaded.Mod.Launcher/Pages/Dialogs/ThemeDownloadDialog.xaml

@@ -16,13 +16,23 @@
 
     <Grid Height="50" Background="{DynamicResource BackgroundBrush}">
         <Grid Margin="6">
-            <Grid Width="485" HorizontalAlignment="Center">
-                <ProgressBar x:Name="ThemeProgressBar"/>
+            <Grid Width="400" HorizontalAlignment="Left">
+                <ProgressBar x:Name="ThemeProgressBar" />
                 <TextBlock
                     x:Name="ThemeTextBlock"
                     HorizontalAlignment="Center"
-                    VerticalAlignment="Center"
-                    Foreground="White"/>
+                    VerticalAlignment="Center">
+                    <TextBlock.Foreground>
+                        <LinearGradientBrush>
+                            <GradientStop Offset="0.0" Color="Black" />
+                            <GradientStop Offset="0.0" Color="White" />
+                        </LinearGradientBrush>
+                    </TextBlock.Foreground>
+                </TextBlock>
+            </Grid>
+
+            <Grid Width="90" HorizontalAlignment="Right">
+                <Button Name="CancelButton" PreviewMouseDown="CancelButton_PreviewMouseDown">Cancel</Button>
             </Grid>
         </Grid>
     </Grid>

source/Reloaded.Mod.Launcher/Pages/Dialogs/ThemeDownloadDialog.xaml.cs

@@ -5,61 +5,91 @@
 
 namespace Reloaded.Mod.Launcher.Pages.Dialogs;
 
+public enum ThemeDownloadDialogResult
+{
+    Ok,
+    Cancelled,
+    Failed
+}
+
+
 /// <summary>
 /// Interaction logic for ThemeDownloadDialog.xaml
 /// </summary>
 public partial class ThemeDownloadDialog : ReloadedWindow
 {
-    private readonly CancellationTokenSource CancellationToken;
-    private readonly Task DownloadTask;
+    private CancellationTokenSource CancellationToken;
 
-    public ThemeDownloadDialog(GameBananaModFile file)
+    public ThemeDownloadDialog()
     {
         InitializeComponent();
 
         CancellationToken = new CancellationTokenSource();
+    }
+
+    // progress is measured from 0-1
+    private void UpdateProgressBar(double progress)
+    {
+        for (int i = 0; i < 2; i++)
+            ((System.Windows.Media.LinearGradientBrush)ThemeTextBlock.Foreground).GradientStops[i].Offset = progress;
 
-        DownloadTask = DownloadAndExtractZip(file);
-        ShowDialog();
-        DownloadTask.Wait();
+        ThemeProgressBar.Value = progress * 100;
     }
 
-    public async Task DownloadAndExtractZip(GameBananaModFile file)
+    public async Task<ThemeDownloadDialogResult> DownloadAndExtractZip(GameBananaModFile file)
     {
+        CancellationToken = new CancellationTokenSource();
+
+        var result = ThemeDownloadDialogResult.Ok;
+
+        UpdateProgressBar(0);
         ThemeTextBlock.Text = $"Downloading {file.FileName}...";
 
         var handler = new HttpClientHandler() { AllowAutoRedirect = true };
         var progressHandler = new ProgressMessageHandler(handler);
 
-        // This is supposed to update the progress bar as it's downloading, emphasis on supposed to
-        progressHandler.HttpReceiveProgress += (obj, args) => { ThemeProgressBar.Value = (args.BytesTransferred / (double)args.TotalBytes!) * 100.0; };
+        progressHandler.HttpReceiveProgress += (obj, args) => { UpdateProgressBar(args.BytesTransferred / (double)args.TotalBytes!); };
 
         int attempts = 0;
         Stream zipStream;
     Retry:
         try
         {
-            zipStream = await new HttpClient(progressHandler).GetStreamAsync(file.DownloadUrl);
+            zipStream = await new HttpClient(progressHandler).GetStreamAsync(file.DownloadUrl, CancellationToken.Token);
         }
-        catch (Exception e)
+        catch
         {
             if (attempts++ < 10)
                 goto Retry;
 
-            var messageBox = new MessageBox("Theme Download Error", "Failed to download the mod! Check your internet connection, and if that's good, it might just be GameBanana's servers acting up, try again later");
+            var messageBox = new MessageBox("Theme Download Error", "Failed to download the theme! Check your internet connection, and if that's good, it might just be GameBanana's servers acting up, try again later");
             messageBox.ShowDialog();
 
+            result = ThemeDownloadDialogResult.Failed;
             // I know, I know, gotos are bad, but in this case it saves a few lines of code -zw
             goto Exit;
         }
 
-        ThemeTextBlock.Text = $"Extracting {file.FileName}...";
-        ZipFile.ExtractToDirectory(zipStream, ThemeDownloader.TempFolder);
+        if (CancellationToken.IsCancellationRequested)
+            result = ThemeDownloadDialogResult.Cancelled;
+        else
+        {
+            ThemeTextBlock.Text = $"Extracting {file.FileName}...";
+            try
+            {
+                ZipFile.ExtractToDirectory(zipStream, ThemeDownloader.TempFolder);
+            }
+            catch
+            {
+                result = ThemeDownloadDialogResult.Failed;
+                goto Exit;
+            }
+        }
 
         zipStream.Close();
 
     Exit:
-        Close();
+        return result;
     }
 
     private void CancelButton_PreviewMouseDown(object sender, MouseButtonEventArgs e)

source/Reloaded.Mod.Launcher/Utility/ThemeDownloader.cs

@@ -238,7 +238,7 @@ private static bool ThemeNeedsToBeCreated(out List<bool> existingXAMLs)
         return createTheme;
     }
 
-    private static void DownloadTheme(GameBananaMod theme)
+    private static async Task DownloadTheme(GameBananaMod theme, ThemeDownloadDialog dialog)
     {
         // There needs to be a standard for how to upload themes
         // I'll support all of the current ones but there's likely to be an edge case that causes it to break in the future -zw
@@ -254,7 +254,8 @@ private static void DownloadTheme(GameBananaMod theme)
 
         if (theme.Files.Count == 1 && theme.Files[0].FileName.EndsWith(".zip"))
         {
-            new ThemeDownloadDialog(theme.Files[0]);
+            if (await dialog.DownloadAndExtractZip(theme.Files[0]) != ThemeDownloadDialogResult.Ok)
+                goto Exit;
 
             if (ThemeNeedsToBeCreated(out var existingXAMLs))
             {
@@ -283,12 +284,13 @@ private static void DownloadTheme(GameBananaMod theme)
         // Checking for the heroes mod loader theme
         else if (theme.Files.Count == 2 && theme.Files[0].FileName == "default_5073e.zip")
         {
-            new ThemeDownloadDialog(theme.Files[0]);
+
+            if (await dialog.DownloadAndExtractZip(theme.Files[0]) != ThemeDownloadDialogResult.Ok) goto Exit;
 
             Directory.Move($"{TempFolder}/Default", themeFolder);
             Directory.Delete(TempFolder);
 
-            new ThemeDownloadDialog(theme.Files[1]);
+            if (await dialog.DownloadAndExtractZip(theme.Files[1]) != ThemeDownloadDialogResult.Ok) goto Exit;
 
             string imagesFolder = $"{themeFolder}/Images";
             Directory.Move(TempFolder, imagesFolder);
@@ -301,20 +303,22 @@ private static void DownloadTheme(GameBananaMod theme)
             CopyFromHalogen($"{ThemeFolder}/Halogen.xaml", themeFolder + ".xaml", themeName);
         }
 
+    Exit:
+        dialog.Close();
         DeleteTempFiles();
     }
 
     /// <summary>
     /// Finds the theme from the given .xaml, and then downloads and installs it
     /// </summary>
     /// <param name="name">The .xaml to load from the theme selector</param>
-    public static void DownloadThemeByName(string name)
+    public static async Task DownloadThemeByName(string name, ThemeDownloadDialog dialog)
     {
         foreach ((var subtheme, var index) in ThemesDictionary)
         {
             if (subtheme == name)
             {
-                DownloadTheme(AvailableThemes[index]);
+                await DownloadTheme(AvailableThemes[index], dialog);
                 break;
             }
         }

source/Reloaded.Mod.Launcher/Utility/XamlThemeSelector.cs

@@ -28,6 +28,27 @@ private void PopulateAndFetch(string selectedTheme, bool fetch=true)
         }
     }
 
+    private async Task DownloadTheme()
+    {
+        string selectedTheme = File!;
+
+        var dialog = new ThemeDownloadDialog();
+        var task = ThemeDownloader.DownloadThemeByName(File, dialog);
+        dialog.ShowDialog();
+        await task;
+
+        bool exists = System.IO.File.Exists(selectedTheme);
+
+        PopulateAndFetch(exists ? selectedTheme : ThemeDownloader.GetFullPath("Default.xaml"), false);
+
+        if (exists)
+        {
+            // Probably the bodgey-est bodge I've ever done -zw
+            File = Files.FirstOrDefault();
+            File = selectedTheme;
+        }
+    }
+
     protected override void UpdateSource()
     {
         if (File == null)
@@ -45,13 +66,8 @@ protected override void UpdateSource()
         }
         catch
         {
-            var selectedTheme = File;
-            ThemeDownloader.DownloadThemeByName(File);
-            PopulateAndFetch(selectedTheme, false);
-
-            // Probably the bodgey-est bodge I've ever done -zw
-            File = Files.FirstOrDefault();
-            File = selectedTheme;
+            DownloadTheme();
+            return;
         }
 
         /*